5.  The applicant was born in 1970 and lives in Berlin.
6.  From Easter to September 2003 the applicant had a relationship with Ms P. In February 2004 Ms P. started a relationship with Mr M. In September 2004 Ms P. and Mr M. moved into a joint household. In October and November 2004 the applicant had intimate contact with Ms P. In December 2004 Ms P. informed the applicant that she was pregnant.
7.  On 28 June 2005 Mr M., with the consent of Ms P., acknowledged paternity of Ms P.’s future child. On 10 August 2005 Ms P. gave birth to a daughter, R. Ms P. and Mr M. jointly exercise parental authority and are bringing up the child together.
8.  On 27 October 2005 the applicant lodged an action to challenge Mr M.’s paternity, submitting a statutory declaration that he had had sexual intercourse with the child’s mother during the period of conception. Mr M. submitted in reply that he lived with the child in a social-familial relationship and that he assumed full parental responsibility for the child, even if he was not her biological father.
9.  On 24 November 2005 the Tempelhof-Kreuzberg District Court (Amtsgericht) scheduled a hearing for 17 January 2006. On 13 January 2006 the District Court cancelled the hearing, as a guardian ad litem to represent the child’s interests had to be appointed. On 6 February 2006 the District Court appointed a guardian ad litem. On 21 March 2006 the guardian submitted that a loving father-child relationship existed between Mr M. and R. and that the applicant’s action ran counter to the child’s best interests.
10.  On 28 March 2006, following a reminder by the applicant’s counsel, the District Court scheduled a hearing for 30 May 2006. On 27 April 2006 the District Court, following M.’s request, postponed the hearing to 6 June 2006.
11.  On 6 June 2006 the District Court, having heard the applicant, Mr M. and Ms P., ordered an expert opinion on the question whether Mr M. was the child’s biological father. On 7 September 2006 the District Court requested the expert to submit information on the state of the proceedings.
12.  On 4 October 2006 the expert informed the District Court that Mr M. and Ms P. had postponed several appointments for the taking of blood samples on medical grounds. Mr M. had his blood sample taken on 4 October 2006. On 2 November 2006 the expert informed the court that he had received the blood samples of Ms P. and the child. On 27 November 2006 the expert submitted his report which concluded that Mr M. was not the child’s biological father.
13.  On 1 December 2006, following a reminder by the applicant’s counsel, the District Court scheduled a further hearing for 16 January 2007. On 6 February 2007 the District Court ordered an expert opinion by the same medical expert as to the applicant’s alleged paternity.
14.  On 15 March 2007 the expert submitted his report which concluded that it had been proved to a probability of 99.99 % that the applicant was the child’s biological father.
15.  On 12 March 2007 the District Court scheduled a hearing for 10 April 2007.
16.  On 27 April 2007 the District Court delivered a judgment establishing that Mr M. was not the child’s father and that the applicant was the child’s father. The District Court found the applicant’s action admissible, as he had submitted a statutory declaration that he had had sexual intercourse with the child’s mother during the period of conception. The action was well-founded, as it had been proved by expert opinion that the applicant was the child’s biological father. The District Court considered that the applicant had not been precluded from challenging paternity under Article 1600 § 2 of the Civil Code (see relevant domestic law below), as there had been no social and family relationship between Mr M. and the child at the time of the last court hearing. It could not be assumed that Mr M. bore actual responsibility for the child. This would have required the legal father and the child to have lived together for a longer period of time, which, according to the District Court, necessitated a minimum period of approximately two years. Taking into account the constitutional right of the biological father under Article 6 § 2 of the Basic Law, it was necessary that the factual relationship between the legal father and the child enjoyed a certain stability. This stability could only be assumed after a period of two years, which had not passed in the instant case. Under these circumstances, it was not relevant that the applicant actually took care of the child together with the child’s mother.
17.  On 24 August 2007 the Berlin Court of Appeal (Kammergericht) quashed the District Court’s judgment and rejected the applicant’s action. The court noted that it was undisputed between the parties that Mr M. had lived with the child and her mother since the child’s birth and that he had continued to live with them after it had been established by an expert that he was not the child’s biological father.
18.  According to the Court of Appeal, the District Court had failed to recognise that the applicant did not have the right to challenge paternity because of the existence of a social and family relationship between Mr M. and the child. The Court of Appeal considered that such a relationship had not only existed at the time it decided on the appeal, but already a long time before, as Mr M. had lived together with the child and her mother in a joint household since the child’s birth. A young child could not possibly live together with another person for a period of time longer than his or her own lifetime. The legislature had not strictly defined which period of time would amount to a “longer period of time”, but had left this assessment to the courts adjudicating each individual case.
19.  The period of time which was necessary to establish a social and family relationship was not absolute, but had to be assessed with regard to the circumstances of each individual case and, in particular, the child’s age. There was no doubt that a child, during the first months of his or her life, developed a social and family relationship with the persons taking care of him or her on a daily basis. During the first two years of his or her life, a child was in particular need of secure family relationships, which allowed him or her to develop further social contacts. A child’s interest in learning about its true descent could only become relevant at a more advanced age. According to the intentions of the legislature, who were guided by the Federal Constitutional Court’s case-law, external disturbances should be avoided in the child’s best interests and in the interest of the already existing family relationship. The constitutional rights of the biological father should not prevail over the equally protected rights of the legal father, if and as long as the latter assumed parental responsibility within the meaning of social parentage. Against this background, even a period of a few months which elapsed between a child’s birth and the bringing of an action to challenge paternity could be considered as a “longer period” within this specific context.
20.  The Court of Appeal did not find it necessary to decide whether the period of time which had elapsed between the child’s birth and the lodging of the applicant’s action would have been sufficient to establish a social and family relationship. According to the case-law of the Federal Law Court, in cases in which the child had lived since birth without interruption together with his or her legal parents, the existence of a social-family relationship had to be assumed if the cohabitation persisted and the judge was convinced that the legal father assumed actual parental responsibility in a way which appeared to be long-lasting. It was not decisive whether the social and family relationship already existed when the action was lodged, but only whether there was a social and family relationship at the time of the last court hearing. The applicant had failed to point to any circumstances which could call into question the existence of such a relationship in the instant case. Conversely, the fact that the relationship between the legal parents had endured the crisis which had been caused by the mother’s breach of trust indicated that the relationship was particularly stable. The Court of Appeal did not allow an appeal on points of law.
21.  On 20 May 2009 the Federal Constitutional Court, sitting as a panel of three judges, refused to admit the applicant’s constitutional complaint for adjudication. This decision was served on the applicant’s counsel on 3 June 2009.